(function (doc, win) {
		  var docEl = doc.documentElement,
			resizeEvt = 'orientationchange' in window ? 'orientationchange' : 'resize',
			recalc = function () {
			  var clientWidth = docEl.clientWidth;
			  if (!clientWidth) return;
			  docEl.style.fontSize = 10 * (clientWidth / 320) + 'px';
			};
	
		  if (!doc.addEventListener) return;
		  win.addEventListener(resizeEvt, recalc, false);
		  doc.addEventListener('DOMContentLoaded', recalc, false);
		})(document, window);
		